Required argument slug_field in SlugRelatedField

[Viicos]

Here's how the __init__ method of SlugRelatedField is looking:

def __init__(self, slug_field=None, **kwargs):
    assert slug_field is not None, 'The `slug_field` argument is required.'
    self.slug_field = slug_field
    super().__init__(**kwargs)

Wouldn't it be better to change slug_field to be a positional argument? Optionally, we could enforce this argument to be kw only:

def __init__(self, *, slug_field, **kwargs):
    ...

[Viicos]

Looks like this would be a breaking change, as it will break for people using it this way: SlugRelatedField(many=True, slug_field="...").